SummaryThe antiapoptotic protein Bcl-2 [1, 2] plays important roles in Ca2+ signaling [3] by influencing inositol triphosphate receptors and regulating Ca2+-induced Ca2+ release [4–6]. Here we investigated whether Bcl-2 affects Ca2+ extrusion in pancreatic acinar cells. We specifically blocked the Ca2+ pumps in the endoplasmic reticulum and assessed the rate at which the cells reduced an elevated cytosolic Ca2+ concentration after a period of enhanced Ca2+ entry. Because external Ca2+ was removed and endoplasmic reticulum Ca2+ pumps were blocked, Ca2+ extrusion was the only process responsible for recovery. Cells lacking Bcl-2 restored the basal cytosolic Ca2+ level much faster than control cells. The enhanced Ca2+ extrusion in cells from Bcl-2 knockout (Bcl-2 KO) mice was not due to increased Na+/Ca2+ exchange activity, because removal of external Na+ did not influence the Ca2+ extrusion rate. Overexpression of Bcl-2 in the pancreatic acinar cell line AR42J decreased Ca2+ extrusion, whereas silencing Bcl-2 expression (siRNA) had the opposite effect. Loss of Bcl-2, while increasing Ca2+ extrusion, dramatically decreased necrosis and promoted apoptosis induced by oxidative stress, whereas specific inhibition of Ca2+ pumps in the plasma membrane (PMCA) with caloxin 3A1 reduced Ca2+ extrusion and increased necrosis. Bcl-2 regulates PMCA function in pancreatic acinar cells and thereby influences cell fate.